🚀 go-pugleaf

>In article <72526@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) w
r
>ites:
>
>>   Now I'm totally confused, Allen. Wasn't this discussion about the
>>   Shuttle's launch rate? I thought that you previously belittled a
>>   25% increase in launch rate, to which I took exception.
>
>Sorry for the misunderstanding. No, I suspect 10 flights a year is possible.
>I doubt 12 can be done without MAJOR changes.
>
>But given the very poor record of Shuttle performance to schedule, I assert
>the burden of proof is on you to show 12 can be done. I'll accept any two
>consecutive calendar years with 24 launches.

     One year doesn't go a long way statistically, but 1992 had a pretty
     good record. Only two launches were late according to the Jan 1992
     launch schedule (STS-45 one day late in March, STS-53 two weeks late
     -due to Discovery's maintenance period- in Nov-Dec.)
     
     Agreed, the proof is in the pudding. Alas, political pressures being
     what they are, NASA is unlikely to get the chance to prove it. Will
     sixteen launches in two years at least give you some cause to believe
     that Shuttle is not yet working at maximum capacity? By the way,
     if Endeavour flies on January 13, that will be nine launches in a
     twelve month period.

>>   I'm still waiting for your explanation as to
>>   why 25% is a good increase for one, but not another.
>
>A DC is simple and reliable enough that 50 flights a year is reasonable
>with the specified ground crew. At 10 flights a year a DC ground crew
>has lots of idle time so not only are more launches possible, they
>will also work to lower costs. Increasing utilization by 25% should
>be no problem (if DC works).

     Essentially the same thing was said in 1972 regarding Shuttle.
     It wasn't true then, but this is the first time I've ever seen
     you use the phrase "if DC works". Heretofor it has been "there's
     no reason it won't work." I've no objection to DC trying, but
     until MD proves it works, let's use what we have to it's utmost
     abilities. 

>With Shuttle, 10 flights a year utilized everything pretty much 100%.
>Adding more flights under these conditions means that costs must go up.

     As you just said, ten per year is 100% of Shuttle's capacity without
     raising costs. So why is Shuttle flying only eight times per year?
     THAT is my complaint.     

>>   it is very difficult to compare
>>   Shuttle with the expendables
>
>Nobody puts people into space just for the hell of it. They are there to
>perform tasks. Given that, one can ask what those tasks are and wonder
>if there are cheaper ways to do those tasks. We can also decide if the
>tasks are worth doing at the price we must pay.

     That is the argument used to justify cancellation of all manned
     space activities. Is that what you are suggesting, Allen?

>I assert that there are no payloads which must fly on Shuttle and are
>worth flying. If you are going to disagree, please do so with a cost
>analysis or your arguement will be meaningless.
>
>Don't you see the damage you are doing to manned space here? Manned space
>is seen as a boondogle and nothing more than a jobs program for aerospace.
>Your astatements that Shuttle must fly regardless of cost only reenforces
>that view. You are making it easier for our opponents to harm us.

     Your claims as to DC's performance before the thing ever flies
     doesn't wow the public, either. I pointed out four recent high
     tech space programs that failed to meet their goals. Besides,
     unless we go buy Soyuz from Russia, what options do we have?
     Please note that I don't support half-empty Shuttles like STS-52,
     or lofting potentially profitable payloads like LAGEOS, but I
     would not be averse to seeing two more Spacelabs on next year's
     schedule instead of being flightless in May/Jun and Sept/Oct.
     
>>   ratings show Shuttle to be the most powerful launch system in the
>>   free world. Depending upon whom you ask, it's either alot more capable
>>   than Titan, or just a little.
>
>There isn't a payload in existance today which can't go up on either.

     Some people say GRO and Hubble are examples, I'm not sure. I've
     seen so many figures for both arguments that I don't know which
     to believe anymore. No single payload is beyond Titan, but Shuttle
     generally flies at about 2/3 capacity. So add another payload.

>As to being more powerful, only if you are spending somebody else's
>money.
>
>>   Only the DC is presently envisioned to have more or less the same
>>   attributes as Shuttle, and we both know there is no way Shuttle can
>>   ever compare favorably to a paper launch system.
>
>This is bogus. By this arguement nothing new should ever be built. If
>you have specific complaints about DC, state them. The arguement 'well
>all projects have problems therefore DC will have problems and therefore
>it won't work' is bullshit.
>
     I see your point, but by the same token you can draw up a nuclear
     powered, seven stage behemoth which could place a few hundred tons
     into LEO. Then you can dig up Delta facts and figures and justify
     its construction.
     
     Specific complaints... I touched on it in the last post. The RL-10.
     You say its simple (a term never before used to describe cryogenic
     powerplants.) I saw beware.
     Ask Russia, which only recently acquired the technology. Ask the
     Japanese, which just postponed H-2 a year because of problems
     with cryogenic engines. Ask Arianespace, most of whose failures are
     due to their cryogenic third stage engine.
     Not a valid argument, you say, because RL-10 has been around since
     the 60s. Okay. In the mid-eighties, General Dynamics began work on
     a Centaur derivative for the Shuttle. P&W also began work on uprated
     RL-10s. This was a proven engine on a proven upper stage. Shouldn't
     have been too much trouble... but it failed twice in eighteen months
     after these modifications. Now MD intends to put an RL-10 on an
     entirely new booster. This MUST require at least as much modification
     as the uprated Centaur. Therefore... prepare yourselves for trouble!
     In the case of the Centaur failures, 50% of the engines failed in
     flight (one of two).
     I am not opposed to DC development, only its proponents who insist
     that its going to be the greatest thing since sliced bread.    

>>   Pegasus was new and revolutionary too, and it has spent the past
>>   eighteen months sitting in an assembly plant.

>More of the same; I'll bet you $50 that it starts flying regularly. Well?

     I'm sure it will too, my point is that it wasn't easy getting there.
     You persistently tell us it will be for DC.
     
     -Brian

-------------------------------------------------------------------------
Brian S. Thorn                                    "If ignorance is bliss,
BrianT@cup.portal.com                               this must be heaven."
                                                -Diane Chambers, "Cheers"
-------------------------------------------------------------------------